This is a mix of multiple dry box parts that I gathered from multiple posts. I tried multiple different variations of other types of spool holders, filament guides, and rod to hold the filament before finding the one that caused the least amount of problems. 

Materials list:

1x 5/16 threaded rod 12" (I used the cheaper zinc, would have picked up the stainless steel one if it was in stock at my local home depot at the time)

2x 5/16 nuts per spool (do not get nyloc nuts as they are just unnecessary)

~8 8-32 machine screws

~8 8-32 nuts

~8 608 bearings

3D printed parts

Basically just some U channel, some rod, and some filament with some holders to place some bearings in (very neccessary to make sure fliament unloads smoothly). If you can't quite figure out how to piece it all together refer to one of the guides listed as they go into great detail.